The present invention relates to an antireflection film and fabrication method thereof, and more particularly to an antireflection film with superior mechanical strength and low reflectivity.
Antireflection film is generally disposed on an outermost surface of an image display device such as optical lens, cathode ray tube display device (CRT), plasma display panel (PDP), liquid crystal display device (LCD), or organic electroluminescent device, to reduce reflectance so as to prevent optical interference from external light.
Single-layer antireflection film provides high yield, simple fabrication process, and low cost, making it a popular display industry choice. Antireflection film of conventional organic compounds containing fluorine used in multi-layer antireflection films, such as CaF2, or MgF2, cannot, however, achieve sufficiently high scratch resistance due to the poor cohesion of fluorine-containing compounds. Thus, a hard coat layer is formed thereon. Furthermore, the antireflection film made thereby has a sufficient refractive index of only 520 to 570 nm, and refractive index thereof cannot be further reduced to 1.40 or less.
A conventional antireflection film with a plurality of nanopores has been disclosed to reduce the refractive index thereof, and FIG. 1 is a schematic view showing the profiles of the antireflection film. Since conventional antireflection film is constructed from stacked silica colloid particles, a plurality of pores occurs among the particles, further lowering reflectance. Accordingly, the conventional antireflection film has a high volume ratio of pores, with mechanical strength thereof depending on the interaction between silica colloid particles. The stacked silica colloid particles, however, are stabilized by intramolecular interaction (van der Waals force) thereof. The conventional antireflection film has low mechanical strength resulting in inferior hardness and scratch resistance thereof, failing to meet the demands of the flat display panel industry.
Therefore, it is necessary to develop an antireflection film with low refractive index and high mechanical strength.